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Depending on age the blower control can be different between 2 different controls. Do you have a circuit board...or a round dial with numbers on the front wall?
ok so on the front wall....is there a vertical box with a round dial in it?
that is for cooling and fan and on...there is a heat sense switch for the heating side...There is a 3rd option if the unit is older than 25 years...and that is a simple bimetal fan switch...I can get a pic for you
see this link for the older style fan switch for heat
post any pics you have and I can check style and circle parts
that is why I ask if you had the circuit board and you said no.
The relays are attached to the circuit board...so when you said no...I went to the older style.
Putting a jumper across the LIMIT will not do anything as the limit is a normally closed contact. Removing the wire from the limit activates the blower as it thinks the switch is open in an overheat state.
Is the only problem at hand the blower not running in heat mode?
The burner fires but trips on limit due to no blower?
Hello,I am a retired mechanical engineer with 56 years in this business. I will go in depth with you, and up to a 6 hour time limit.
All I ask is please select the ***RATING LINK*** at the top of your page before leaving, that is the only way I am credited through the site.
Rating does not affect your charges nor ability to refund if not satisfied. If you can agree to that, lets continue by all means
please attach a close up photo of the furnace wiring diagram that is glued to the inside of the blower access door....it must be well lit and ***exceedingly well focused, I will mark it up with trouble shooting instructions.
Use the attach files link next to your send button to get the photo to me
Its set up for posting photo's to this dialog box. It creates an open record fo answerr quality control purposes.
Hello again, click here, this is all I could find, Does that wiring diagram on page 28 match your wiring diagram?
We can go from there
Ooops click here please
click here please, set the thermostat on heating and up to 90F, then measure the voltage between C and W marked in red....if you do not have 24vac there, fit a jumper wire between R and W as shown in blue. Tell me what you discovered.
That jumper between R and W is just for a brief test, do not leave it in place
click here please, if you do not have 24vac between R and C marked in light blue, check that wire nut circled in red for a bad connection going to C on the fan relay.
If you have 24vac between R and C, fit the jumper shown in green on the fan relay.
take your time, make sure your test probes are making good contact before deciding if there is voltage read or not.
We can go from there, respond in the simplest sentences possible. Avoid mixing comments or speculations or other questions with what you find or do not find. We will get to that in due time.